GiffGaff come it for a fair bit of criticism here, but I don't think anyone comes close for price any more. It depends how important data is to you though, I find their speeds often poor, and that's poor by 3G standards.
I wouldn't rule out a contract as long as you don't mind being tied to them. SIM only prices have gone up a lot and I don't think its necessarily always the cheaper option now.
I wouldn't rule out a contract as long as you don't mind being tied to them. SIM only prices have gone up a lot and I don't think its necessarily always the cheaper option now.